1. Field of the Invention
The present invention relates to a locking device for the automatic shift lever of a car which can lock, in an easy way, a control link in a knob for the shift lever, such that the shift lever is unable to operate such that a theft-proof effect can be achieved.
2. Description of the Prior Art
Theft-proof devices for automobiles in the market are divided into three kinds, theft-proof bells, steering wheel locks, and shift lever locks, the principles and disadvantages of each being as follows:
1) a theft-proof bell uses a balancing principle to allow the switch of a buzzer to be turned on for scaring a thief; however, if a passenger inadvertently touches the car body, or even when vibrating is effected by a car passing by, the bell will make a loud noise which can affect the quiet and peaceful moods of people. The theft-proof bell is powered by the battery of the car, so that the car is subjected to electricity losses even when parking.
2) a steering wheel lock provides a lock head in the middle of a bar, it can be placed on the surface of the steering wheel, with the two ends of the bar abutting against both sides thereof, so as to limit the steering wheel from rotating; or an extendible hooking bar can be used to lock the steering wheel by locking of the lock head with one end of the bar hooking the steering wheel and the other end hooking the pedal of the accelerator and having the length therebetween adjustable. However, this is bothersome in use and some drivers hate to use the steering wheel lock as it adds too much time to parking, while theft of a car often happens in a short time.
3) a shift lever lock provides a lock head at one side of the seat for the shift lever (referring to FIG. 10), with a pivotally connecting hole on the lock head facing the shift lever and engaged by a U-shaped locking hook to lock the shift lever and thus prevent the same from moving. However, when the lock is opened or closed, a driver must turn his body to insert a key into the lock hole with one hand, and to draw away or engage the lock head from/with the U-shaped locking hook with another hand. This is a quite unconvenient task to perform with two hands in a narrow space in a car.
In view of the above-stated disadvantages of conventional theft-proof car locks, the inventor of the present invention has heretofore developed a delicate lock structure which causes a stop piece on a lever lock to stop a control link, thereby preventing a control button from being pressed down and pushing rearwardly the control link, and therefore in turn to prevent moving of a shift control rod, so that the automatic shift lever cannot be moved. The object of locking can thus be achieved, and with this, any disadvantage or unconvenience in operation and assembling in the conventional U-shaped locking hook and lock head used for locking the shift lever can be eliminated. However, it can be seen from FIG. 10 that when a shift control rod 4' is pressed down in a normal shifting action, a limiting rod 41" extending sidewardly on the bottom end thereof will move downwardly to be free from engagement in a guiding groove 51' on a guiding plate 5', so that the shift lever 6' can be moved forwardly and backwardly freely, i.e., so long as the limiting rod 41' is free from engagement in the guiding groove 51', the shift lever 6' can be moved; in other words, if a thief is familiar with the way of locking of the invention and the principle of operation of the automatic shift lever, he can then use an iron sheet to insert into the gap between the shift lever 6' and the seat 61' for the shift lever 6', to twist and press the same, as long as it presses the limiting rod 41' to move down the shift control rod 4', the shift lever 6' can be shifted. In this way, the lock structure will be of no use. The way to open it is not so easy for a thief to know, because he must know well the manner of locking as well as the structure of the car,nevertheless, this is a concern and warrants that the lock structure for the automatic shift lever of the car has to be redesigned.